Bolt-heading machine



UNITED sTATEs PATENT oEEioE.,

WM. GRANT, OF BOSTON, MASSACHUSETTS.

BOLT-HEADING MACHINE.

Specification of Letters Patent No. 5,986, dated Decemberl 26, 1848..

T 0 all whom/15 may concern:

Be it known that I, WILLIAM GRANT, of Boston, in the county of Suolk and State of Massachusetts, have invented a new and useful Machine for the Purpose of Forming by Compression Prismatic Heads of Three or More Sides on Metallic Bolts, of which the'following is a full and exact description, reference being had to the annexed drawings of the same, making part of this speciication, in which- Figure l is a-n isorrr'etrical perspective view of the machine showing the several parts in connection, and ready for operation, Fig. 2 is a vertical longitudinal section through the line ll'of Fig. 1, and Fig. 3

is a vertical transverse section taken through the line 22 of Fig. l, Fig. 4 is a sectional view, showing the form ofthe head when flattened by the first stroke of the punch, before being acted upon by the dieser swage. The same letters indicate the same parts in all the iigures. v

Numerous attempts have been made to form square and other angular headson metallic bolts by compressing a portion of the rod to the proper shape by means of automatic machinery, but heretofore with only partial success, none of the machines tried having been found capable of producing heads with uniformly sharp and welldefined angles. The only way in which headed bolts are now made, either upon a large or small scale, is by hand, forging with hammer and swages upon an anvil, in the primitive method. The cause of these repeated failures to make heads on bolts by machinery, is to be found in part in the refractory nature of iron, and its deciency in the quality of plasticity, even when heated to as high a degree as it will admit of without permanent injury to its strength. Another of the causes which has contributed to these failures is the total want of adaptation in the mode of action, and structure of the machines used, to those methods of operating upon t-he metal, which manipulation upon the anvil'has demonstrated to be essential to the production of angular heads of a definite form and size. They have all been constructed upon the plan of attempting to compress a portion of they end of the bolt into a mold of the required formy and size, by the direct action, and at one operation of a piston or punch fitting therein. But the smith always proceeds first to upset greater the end of the bolt, until itI is of the form of a thick disk of'considerably larger diameter and proportionately shorter than the required head, and then hammers this disk into the desired number 4of sides and angles, in doing which it is reduced to the diameter and increased to the length required. Now this 1s precisely the plan upon which my ymachine operates, having constructed it solely with a view of imitating as closely as -'possible the mostv approved methods of manipulation, fromwhich its action differs only in being capable kof working with power, velocity, and accuracy, whereby a superior bolt is produced at a diminished cost.

The frame A, represented inthe accom- B and C are respectively strong shafts well secured in suitable bearingsmade in the frame A at right angles to each other, and are connected together with cog wheels, in order that one may drive the other and the mot-ions of both be equal and simulta- Y The cam D is either cast in one solid piece with the shaft B, or firmly secured thereon, by screws, keys, or otherwise. This cam operates the punch E which upsets the end of the bolt, and is so formed as to give the. y:

same, two strokes in revolution. f n

The cams F and G are respectively cast quick succession at each in one piece with, or firmly secured to the` ci, shaft C, the former cam F closing 'the mov-A able jaw H of the clamp, andthe latter operating the movable half-of the die or swage I in which the head is formed.

J is an adjustable sliding block orfrest, placed in a mortise made through theend piece of the frame, and held firmly therein i in. any position in which'it may be adjusted by agclamp screw. Longitudinally through this sliding block a hole o is made of a diameter just. enough'larger thanthe rod being operated onto admit ofthe v'same being pushed through it with ease, this hole is made throughthe block a distance equalto l 4about its own diameter from the centerof the opening between the aws of the clamp,

` fixed in its place by screws or otherwise, and

the jaw H is securely held in the recess, but not too tightly to admit of its sliding freely, bythe cap K. The adjacent ends .of these jaws are of the precise length which 1t is required to make the shank of the bolt, and have parallel creases made 1n them, which when the ends meet form a cylindrical or other shaped hole, which in diameter and form corresponds with the bolt being headed.

The movable aw H of the clamp as it closes, slides against the inner end of the adjustable rest J, and clips ofi' the end of the rod which is protruded through the same. v

The fixed and movable halves I, I of the swage or die in which the head is formed, are placed in the same recesses with the fixed and movable clamp jaws H H, and being of the same thickness, and of an uni form width throughout, they are secured in place at the same time and by the same means as the jaws. The movable jaw of the clamp and the movable die, are' held back against the cams by means of a spring, as is also the punch E. The adjacent ends of the die blocks have each a semi-prismatic recess made in them, of the precise form and size of one half of the head which it is required to make on th'e bolt, the hole formed by the junction of these recesses when the dies are closed being parallel to and concentric with, that formed bythe meeting of the jaws of the clamp in which the shank of the bolt is held. j Y

A series of yclamp jaws H H', dies for the head I I and sliding rests J must be provided, as numerous as the different diameters of bolts required to be made, with a further increase of the number of clamp aws equal to the sum of the different lengths of each size of bolt, as a distinct pair ofclamp jaws is required for every variation in any of the, dimensions of the bolts. As many sets of head swages or dies must also be provided, as there are different forms of heads.

The punch E is placedfparallel to and conf centric with the die, and rests in, and4 is guided by a mortise made through the cross bar of the frame which is strengthened by lbosses on its upper and under. sides to Vcompensate for the weakening occasioned by this mortise.

Upon either ofthe shafts a pulley or cog` wheel may be placed for the purpose of communicating motion to the apparatus from a steam engine, or any other convenient or available source. The rods to be cut up into bolts and headed, are made White hot in a furnace which is placed near the end of the machine, in order that they may be'jtransferred from the former to the lat-ter `with the least vpossible loss of heat.

The motions of the clamp, dies, and punch may be effected by means of cranks, toggle Preparatory to commencing operations a quantity of rods must be heated in the furnace to the required temperature. The clamp plates dies and rest must be of `the proper size and form, and duly adjusted in their respective places. The machine being then put in motion the attendant seizes with his tongs, one of the hottest rods, and pushes it rapidly throughA the aperture Z2 of the rest until its end strikes the punch E, when it is instantly cut off bythe closing of the clamp jaw H, and held with one end aga-inst the rest J, the other protruding between the swages a length suficient to fur nish the requisite quantity of metal to form the head, the clamp is then closed, and the rod held in it by the cam F acting against the movable'jaw H. Simultaneously with the closing of the clamp by the action of the cam F, the cam G causes the `movable swage I to approach within about one eighth of t-he required diameter of the head of the bolt vof its fixed counterpart I where it remains stationary for a moment, and in the mean time the cam D by its projection m pushes the punch E with great force into the die, compressing. or upsetting the end of the bolt therein, into a shape approximating to the form of the dies, but'about one eighth greater in diameter, `and proprtionately shorter than the finished head is required to be, the punch is then quickly withdrawn bv the action of a spring or otherwise, and the cam G by a continuance of its motion, bringing its point of greatest eccentricity to act against the movable swage I forces it up into contact. with the fixed part I compressing the flattened head to the required diameters "in doing which all the angles of theswage are filled, then the punch` by th action .of the projection??l of the cam D is a secondtime forced against the head, which makes the end and every part of the head smooth, even, and of the exact form of the die, parallel to, and concentric with the bolt,

and in all respects as accurate as can be made by any means whatever, or as is required for any purpose. The bolt is now complete, thecams present their sides of least eccentricity to the clamp, swage and punch,l

which are thus left free to be moved back by the` springs (m m), the bolt drops down and out, and the machine is again ready to receive the end of the rodv from which to make another bolt by a repetition of the process just described. l

It is obvious that any number of bolts can thus be made of a uniform size and form, neither using too much nor too little material, an advantage, the importance of which may be inferred from the fact that all hand made bolts have to be trimmed'to the proper size after being forged and the loss caused by this operation from the diminished value of the pieces of metal thus cut off and reduced to the form of scrap, amounts where bolts are made upon a large scale, to a very considerable item'in the course of the year. In addition to this saving of matrial ay great saving of fuel is also effected by the use of my machine, as it is capable of performing the work of at least ten forge fires, and the bolt rods being heated in a furnace it will not consume more fuelthan one of these fires. Those ten forgeres would require ten smiths and ten assistants, but my machine to perform the same labor would only require one attendant to feed it with rods and thus the labor of nineteen men, and nine tenths of the fuel consumed by the ordinary hand process, is saved.

The cost of the excess of power required by this machine, over what would be sufficient to blow the forge lires, is of course to be deducted fromthe above estimated saving, but as three or four bushels of coal per diem would produce it, it is but a small item. These statements are of course only approximative, but it is believed that'they willnot be found very far from the truth.

The uniformity, accuracy, and truth with which the heads are formed, and the precision with which they are placedconcentric with the axis of the rod, and with their ends at rightA angles thereto, if of great importance from considerations entirely independent of the saving in the cost of manufacture, for when the shoulder of the head is irregular, it bears upon its seat only on one side, and if in bringing it home the nut` be turned a little too hard, the head will eihter be broken off, or the neck so much weakened as to render it liable to give way the first time it is subjected to a heavy strain,

my invention. Nor do I claim to have dis-k covered that chilled cast iron is capable of resisting a higher temperature without being softened than caststeel. Neitherl do I claim its use in the constructi'onfof ma-L chinery generally, for the purpose of working heated metals; nor for voperating upon metals in a cold state--but What I do claim as myv invention, and desire to secure by -Letters Patent, is

The formation of heads on bolts by macliinery by -first upsetting or compressing into a partially closed die, a portion of the rod, by

means of a punch, into a shape approximating to the form required, but of larger diameter, andproportionately shorter, and then, by entirely closing the dies and again forcing up the punch reducing it to the proper proportions, and completing its form as herein set forth, whether the devices by which the several motions are produced, be such as are herein described, or others capable of effecting the same results.

In testimony whereof I have hereunto signed my name 1n presence of two witnesses.

p WM. GRANT. Witnesses S. N. VVooD, P. H. WATSON. 

